Insulator layer based mems devices

ABSTRACT

The present invention relates to using an insulator layer between two metal layers of a semiconductor die to provide a micro-electromechanical systems (MEMS) device, such as an ohmic MEMS switch or a capacitive MEMS switch. In an ohmic MEMS switch, the insulator layer may be used to reduce metal undercutting during fabrication, to prevent electrical shorting of a MEMS actuator to a MEMS cantilever, or both. In a capacitive MEMS switch, the insulator layer may be used as a capacitive dielectric between capacitive plates, which are provided by the two metal layers. A fixed capacitive element may be provided by the insulator layer between the two metal layers. In one embodiment of the present invention, an ohmic MEMS switch, a capacitive MEMS switch, a fixed capacitive element, or any combination thereof may be integrated into a single semiconductor die.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/181,356, filed Jul. 29, 2008, the disclosure of which is incorporatedherein by reference in its entirety.

FIELD OF THE DISCLOSURE

Embodiments of the present invention relate to micro-electromechanicalsystems (MEMS) devices integrated into a semiconductor die. The MEMSdevices may be used in tunable or adaptive circuits.

BACKGROUND

As technology progresses, geometries of integrated circuits becomesmaller and smaller. Increasing varieties and quantities of circuitelements are integrated into semiconductor dies to reduce sizes andcosts of electronics equipment. Tuning and adaptive circuits are twotypes of circuits commonly used in electronics circuits. An example of atuning circuit is a digitally-controlled oscillator (DCO) used in afrequency synthesizer. The DCO may use a resonant circuit having aninductance and a capacitance to establish an oscillator frequency forthe DCO. The capacitance may be provided by a selectable capacitor bank10 as illustrated in FIG. 1, according to the prior art.

The selectable capacitor bank 10 includes a first capacitive element C1,a second capacitive element C2, up to and including an Nth capacitiveelement CN, a first switch 12, a second switch 14, up to and includingan Nth switch 16, and control circuitry 18. Each of the capacitiveelements C1, C2, CN is coupled in series with each of the switches 12,14, 16, respectively, and each capacitive element and switch seriescoupling is coupled between a first terminal FT and a second terminalST. A control terminal of each of the switches 12, 14, 16 is coupled toand controlled by the control circuitry 18, which receives controlinformation via a control interface CONT. The frequency of the DCO istuned by controlling the capacitance of the selectable capacitor bank10, based on the control information, by selecting the appropriatecombination of capacitive elements C1, C2, CN to provide the desiredcapacitance. Thus, there is a need to integrate capacitive elements C1,C2, CN and switches 12, 14, 16 into a common semiconductor die.

Micro-electromechanical systems (MEMS) devices, such as MEMS switches,are often integrated into semiconductor dies. However, as geometries ofintegrated circuits become smaller and smaller, fabrication of MEMSdevices may become increasingly problematic. FIG. 2 shows a MEMS switch20, according to the prior art. The MEMS switch 20 includes a cantilever22 having a movable contact 24, a fixed contact 26 electrically coupledto a first terminal 28, a second terminal 30 electrically coupled to themovable contact 24, and an actuator 32 electrically coupled to a controlterminal 34. When the MEMS switch 20 is actuated by applying anactuation signal to the control terminal 34, the movable and fixedcontacts 24, 26 come together, thereby closing the MEMS switch 20. Whenthe MEMS switch 20 is closed, the touching movable and fixed contacts24, 26 have some contact resistance; therefore, the MEMS switch 20 iscalled an ohmic MEMS switch. When the MEMS switch 20 is not actuated byremoving the actuation signal from the control terminal 34, the movableand fixed contacts 24, 26 move apart, thereby opening the MEMS switch20.

During actuation, if the geometries of the MEMS switch 20 aresufficiently small, there may be a risk of the cantilever 22 shorting tothe actuator 32. Additionally, the actuator 32 may be formed using afirst metal layer (not shown) and the cantilever 22 may be formed usinga second metal layer (not shown). Therefore, when the second metal layeris etched to form the cantilever 22, the metal actuator 32 may beundercut. Thus, there is a need to prevent cantilever 22 to actuator 32shorting and to prevent metal undercutting of the actuator 32 in a MEMSswitch 20.

SUMMARY

The present invention relates to using an insulator layer between twometal layers of a semiconductor die to provide a micro-electromechanicalsystems (MEMS) device, such as an ohmic MEMS switch or a capacitive MEMSswitch. In an ohmic MEMS switch, the insulator layer may be used toreduce metal undercutting during fabrication, to prevent electricalshorting of a MEMS actuator to a MEMS cantilever, or both. In acapacitive MEMS switch, the insulator layer may be used as a capacitivedielectric between capacitive plates, which are provided by the twometal layers.

A fixed capacitive element may be provided by the insulator layersandwiched between the two metal layers. In one embodiment of thepresent invention, an ohmic MEMS switch, a capacitive MEMS switch, afixed capacitive element, or any combination thereof may be integratedinto a single semiconductor die. Combined switching elements andcapacitive elements may be used in tunable or adaptive circuits, such asadaptive MEMS driver circuitry, frequency synthesizers, tunable radiofrequency (RF) impedance matching circuits, or the like.

Those skilled in the art will appreciate the scope of the presentinvention and realize additional aspects thereof after reading thefollowing detailed description of the preferred embodiments inassociation with the accompanying drawing figures.

Those skilled in the art will appreciate the scope of the disclosure andrealize additional aspects thereof after reading the following detaileddescription in association with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawing figures incorporated in and forming a part ofthis specification illustrate several aspects of the invention, andtogether with the description serve to explain the principles of theinvention.

FIG. 1 shows a selectable capacitor bank, according to the prior art.

FIG. 2 shows a micro-electromechanical systems (MEMS) switch, accordingto the prior art.

FIG. 3A shows the MEMS switch illustrated in FIG. 2 and FIG. 3B shows afirst insulated-actuator MEMS switch, according to one embodiment of thepresent invention.

FIG. 4A shows a first MEMS switching capacitive element, according to analternate embodiment of the present invention.

FIG. 4B shows an alternate MEMS switching capacitive element, accordingto another embodiment of the present invention.

FIG. 4C shows a first integrated fixed capacitive element, according toan additional embodiment of the present invention.

FIG. 5 shows an integrated selectable capacitor bank, according to oneembodiment of the present invention.

FIG. 6 shows a first region of a semiconductor die, according to oneembodiment of the present invention.

FIG. 7 shows a first patterned photoresist layer added to thesemiconductor die illustrated in FIG. 6.

FIG. 8 shows a first metallic adhesion layer and a first metallicstructural layer added to the semiconductor die illustrated in FIG. 7.

FIG. 9 shows the remnants of the first metallic adhesion layer and thefirst metallic structural layer after lifting-off the portions of thefirst metallic adhesion layer and the first metallic structural layerthat were formed over the first patterned photoresist layer asillustrated in FIG. 8.

FIG. 10 shows a second patterned photoresist layer and a firstmetallization layer added to the semiconductor die illustrated in FIG.9.

FIG. 11 shows the remnants of the first metallization layer afterlifting-off the portion of the first metallization layer that was formedover the second patterned photoresist layer as illustrated in FIG. 10.

FIG. 12 shows a third insulator layer and a third patterned photoresistlayer added to the semiconductor die illustrated in FIG. 11.

FIG. 13 shows the remnants of the third insulator layer after etchingaway a portion of the third insulator layer illustrated in FIG. 12.

FIG. 14 shows a first sacrificial layer and a fourth patternedphotoresist layer added to the semiconductor die illustrated in FIG. 13.

FIG. 15 shows the remnants of the first sacrificial layer after etchingaway a portion of the first sacrificial layer and shows a secondmetallization layer added to the semiconductor die illustrated in FIG.14.

FIG. 16 shows a patterned photoresist mold and a MEMS cantileverstructure layer added to the semiconductor die illustrated in FIG. 15.

FIG. 17 shows the remnants of the second metallization layer and theMEMS cantilever structure layer after etching away a portion of thesecond metallization layer and the MEMS cantilever structure layerillustrated in FIG. 16.

FIG. 18 shows a patterned second sacrificial layer added to thesemiconductor die illustrated in FIG. 16.

FIG. 19 shows a dome layer added to the semiconductor die illustrated inFIG. 18 to provide the first insulated-actuator MEMS switch.

FIG. 20 shows a second region of the semiconductor die, according to oneembodiment of the present invention.

FIG. 21 shows the second patterned photoresist layer and the firstmetallization layer added to the semiconductor die illustrated in FIG.20.

FIG. 22 shows the remnants of the first metallization layer afterlifting-off the portion of the first metallization layer that was formedover the second patterned photoresist layer as illustrated in FIG. 21.

FIG. 23 shows the third insulator layer and the third patternedphotoresist layer added to the semiconductor die illustrated in FIG. 22.

FIG. 24 shows the remnants of the third insulator layer after etchingaway a portion of the third insulator layer illustrated in FIG. 23.

FIG. 25 shows the first sacrificial layer and the fourth patternedphotoresist layer added to the semiconductor die illustrated in FIG. 24.

FIG. 26 shows the remnants of the first sacrificial layer after etchingaway a portion of the first sacrificial layer and shows the secondmetallization layer added to the semiconductor die illustrated in FIG.25.

FIG. 27 shows the patterned photoresist mold and the MEMS cantileverstructure layer added to the semiconductor die illustrated in FIG. 26.

FIG. 28 shows the remnants of the second metallization layer and theMEMS cantilever structure layer after etching away a portion of thesecond metallization layer and the MEMS cantilever structure layerillustrated in FIG. 27.

FIG. 29 shows the second sacrificial layer after patterning and etchingadded to the semiconductor die illustrated in FIG. 28.

FIG. 30 shows the dome layer added to the semiconductor die illustratedin FIG. 29 to provide the first MEMS switching capacitive element.

FIG. 31 shows a third region of the semiconductor die, according to oneembodiment of the present invention.

FIG. 32 shows the second patterned photoresist layer and the firstmetallization layer added to the semiconductor die illustrated in FIG.31.

FIG. 33 shows the remnants of the first metallization layer afterlifting-off the portion of the first metallization layer that was formedover the second patterned photoresist layer as illustrated in FIG. 32.

FIG. 34 shows the third insulator layer and the third patternedphotoresist layer added to the semiconductor die illustrated in FIG. 33.

FIG. 35 shows the remnants of the third insulator layer after etchingaway a portion of the third insulator layer illustrated in FIG. 34.

FIG. 36 shows the patterned photoresist mold and the MEMS cantileverstructure layer added to the semiconductor die illustrated in FIG. 35.

FIG. 37 shows the remnants of the second metallization layer and theMEMS cantilever structure layer after etching away a portion of thesecond metallization layer and the MEMS cantilever structure layerillustrated in FIG. 36 to provide the first integrated fixed capacitiveelement.

FIG. 38 shows an application example of the present invention used in amobile terminal.

DETAILED DESCRIPTION

The embodiments set forth below represent the necessary information toenable those skilled in the art to practice the invention and illustratethe best mode of practicing the invention. Upon reading the followingdescription in light of the accompanying drawing figures, those skilledin the art will understand the concepts of the invention and willrecognize applications of these concepts not particularly addressedherein. It should be understood that these concepts and applicationsfall within the scope of the disclosure and the accompanying claims.

The present invention relates to using an insulator layer between twometal layers of a semiconductor die to provide a micro-electromechanicalsystems (MEMS) device, such as an ohmic MEMS switch or a capacitive MEMSswitch. In an ohmic MEMS switch, the insulator layer may be used toreduce metal undercutting during fabrication, to prevent electricalshorting of a MEMS actuator to a MEMS cantilever, or both. In acapacitive MEMS switch, the insulator layer may be used as a capacitivedielectric between capacitive plates, which are provided by the twometal layers.

A fixed capacitive element may be provided by the insulator layerbetween the two metal layers. In one embodiment of the presentinvention, an ohmic MEMS switch, a capacitive MEMS switch, a fixedcapacitive element, or any combination thereof may be integrated into asingle semiconductor die. Combined switching elements and capacitiveelements may be used in tunable or adaptive circuits, such as adaptiveMEMS driver circuitry, frequency synthesizers, tunable radio frequency(RF) impedance matching circuits, or the like.

FIG. 3A shows the MEMS switch 20 illustrated in FIG. 2 and FIG. 3B showsa first insulated-actuator MEMS switch 36, according to one embodimentof the present invention. The first insulated-actuator MEMS switch 36 isan ohmic MEMS switch similar to the MEMS switch 20 illustrated in FIG.3A. However, the first insulated-actuator MEMS switch 36 includes anactuator insulator 38 over the actuator 32. The actuator insulator 38may prevent shorting of the cantilever 22 to the actuator 32 when thefirst insulated-actuator MEMS switch 36 is actuated, may reduce orprevent metal undercutting of the actuator 32 during fabrication, orboth.

FIG. 4A shows a first MEMS switching capacitive element 40, according toan alternate embodiment of the present invention. The first MEMSswitching capacitive element 40 includes a cantilever 42, whichfunctions as a movable capacitive plate, a first terminal 44electrically coupled to a fixed capacitive plate 46, a second terminal48 electrically coupled to the cantilever 42, an actuator 50electrically coupled to a control terminal 52, and a capacitivedielectric 54. The movable capacitive plate, the capacitive dielectric54, and the fixed capacitive plate 46 form a selectable capacitiveelement.

When no actuation signal is applied to the control terminal 52, thefirst MEMS switching capacitive element 40 is not actuated. Therefore,non-actuated spacing between the movable capacitive plate and the fixedcapacitive plate 46 establishes a first capacitance presented to thefirst and second terminals 44, 48. However, when an actuation signal isapplied to the control terminal 52, the first MEMS switching capacitiveelement 40 is actuated, thereby moving the cantilever 42 closer to thefixed capacitive plate 46. Therefore, actuated spacing between themovable capacitive plate and the fixed capacitive plate 46 establishes asecond capacitance presented to the first and second terminals 44, 48.The second capacitance is greater than the first capacitance due to thereduced spacing between the movable capacitive plate and the fixedcapacitive plate 46.

The capacitive dielectric 54 insulates the cantilever 42 from the fixedcapacitive plate 46. In one embodiment of the present invention, thecapacitive dielectric 54 may prevent shorting of the cantilever 42 tothe actuator 50 when the first MEMS switching capacitive element 40 isactuated, may reduce or prevent metal undercutting of the actuator 50during fabrication, or both.

FIG. 4B shows an alternate MEMS switching capacitive element 56,according to another embodiment of the present invention. The alternateMEMS switching capacitive element 56 includes the cantilever 42, whichfunctions as a movable capacitive plate, the first terminal 44electrically coupled to a combined actuator and fixed capacitive plate57, the second terminal 48 electrically coupled to the cantilever 42,and the capacitive dielectric 54. The movable capacitive plate, thecapacitive dielectric 54, and the combined actuator and fixed capacitiveplate 57 form a selectable capacitive element.

When no actuation signal is applied to the first terminal 44, thealternate MEMS switching capacitive element 56 is not actuated.Therefore, non-actuated spacing between the movable capacitive plate andthe combined actuator and fixed capacitive plate 57 establishes a firstcapacitance presented to the first and second terminals 44, 48. However,when an actuation signal is applied to the first terminal 44, thealternate MEMS switching capacitive element 56 is actuated, therebymoving the cantilever 42 closer to the combined actuator and fixedcapacitive plate 57. Therefore, actuated spacing between the movablecapacitive plate and the combined actuator and fixed capacitive plate 57establishes a second capacitance presented to the first and secondterminals 44, 48. The second capacitance is greater than the firstcapacitance due to the reduced spacing between the movable capacitiveplate and the combined actuator and fixed capacitive plate 57.

The capacitive dielectric 54 insulates the cantilever 42 from thecombined actuator and fixed capacitive plate 57. In one embodiment ofthe present invention, the capacitive dielectric 54 may prevent shortingof the cantilever 42 to the combined actuator and fixed capacitive plate57 when the alternate MEMS switching capacitive element 56 is actuated,may reduce or prevent metal undercutting of the combined actuator andfixed capacitive plate 57 during fabrication, or both. In one embodimentof the present invention, in addition to the first terminal 44, acontrol terminal 52 may be electrically coupled to the combined actuatorand fixed capacitive plate 57.

FIG. 4C shows a first integrated fixed capacitive element 58, accordingto an additional embodiment of the present invention. The firstintegrated fixed capacitive element 58 includes a first capacitive plate59 electrically coupled to a first terminal 60, a second capacitiveplate 62 electrically coupled to a second terminal 64, and a fixeddielectric 66, which is between the first and second capacitive plates59, 62. The first and second capacitive plates 59, 62 and the fixeddielectric 66 form a capacitive element with a capacitance presented tothe first and second terminals 60, 64.

FIG. 5 shows an integrated selectable capacitor bank 68, according toone embodiment of the present invention. The integrated selectablecapacitor bank 68 includes the first integrated fixed capacitive element58, a second integrated fixed capacitive element 70, the firstinsulated-actuator MEMS switch 36, a second insulated-actuator MEMSswitch 72, the first MEMS switching capacitive element 40, a second MEMSswitching capacitive element 74, and control circuitry 76. Each of theintegrated fixed capacitive elements 58, 70 is coupled in series witheach of the insulated-actuator MEMS switches 36, 72, respectively, andeach capacitive element and switch series coupling is coupled between afirst terminal FT and a second terminal ST. Additionally, each of theMEMS switching capacitive elements 40, 74 is coupled between the firstterminal FT and the second terminal ST.

A control terminal of each of the insulated-actuator MEMS switches 36,72 and each of the MEMS switching capacitive elements 40, 74 is coupledto and controlled by the control circuitry 76, which receives controlinformation via a control interface CONT. The capacitance of theintegrated selectable capacitor bank 68 is presented to the first andsecond terminals FT, ST. An external device (not shown) controls thecapacitance of the integrated selectable capacitor bank 68 based on thecontrol information by selecting the appropriate combination ofintegrated fixed capacitive elements 58, 70 and selected MEMS switchingcapacitive elements 40, 74 to provide the desired capacitance. Inalternate embodiments of the present invention, any or all of the firstintegrated fixed capacitive element 58, the second integrated fixedcapacitive element 70, the first insulated-actuator MEMS switch 36, thesecond insulated-actuator MEMS switch 72, the first MEMS switchingcapacitive element 40, and the second MEMS switching capacitive element74 may be omitted. Further, additional insulated-actuator MEMS switches36, 72, MEMS switching capacitive elements 40, 74, integrated fixedcapacitive elements 58, 70, or any combination thereof, may be included.

FIG. 6 shows a first region of a semiconductor die 78, according to oneembodiment of the present invention. The semiconductor die 78 includes asubstrate 80, which may be a semiconductor substrate, such as Silicon. Asubstrate insulator layer 82 is over the substrate 80 and includes afirst insulator layer 84 and a second insulator layer 86. The firstinsulator layer 84 may include Silicon Nitride and the second insulatorlayer 86 may include Silicon Dioxide. In alternate embodiments of thepresent invention, the substrate insulator layer 82 may be a singlelayer, may include multiple layers, the first insulator layer 84 mayinclude other insulating material, the second insulator layer 86 mayinclude other insulating material, or any combination thereof.

FIG. 7 shows a first patterned photoresist layer 88 added to thesemiconductor die 78 illustrated in FIG. 6 and formed over the secondinsulator layer 86. FIG. 8 shows a first metallic adhesion layer 90 anda first metallic structural layer 92 added to the semiconductor die 78illustrated in FIG. 7. The first metallic adhesion layer 90 is formedover the first patterned photoresist layer 88 and the second insulatorlayer 86. The first metallic structural layer 92 is formed over thefirst metallic adhesion layer 90, which may include Titanium, Chromium,Titanium Tungsten alloy, or other suitable material, and is used to bondthe first metallic structural layer 92 to the substrate insulator layer82. The first metallic structural layer 92 may include Gold, Copper, orAluminum.

FIG. 9 shows the remnants of the first metallic adhesion layer 90 andthe first metallic structural layer 92 after lifting-off the portion ofthe first metallic adhesion layer 90 and the first metallic structurallayer 92 that were formed over the first patterned photoresist layer 88as illustrated in FIG. 8. The remnants of the first metallic adhesionlayer 90 and the first metallic structural layer 92 provide a bump,which will be used to form the fixed contact 26 of the firstinsulated-actuator MEMS switch 36. Alternate embodiments of the presentinvention may use other techniques to form the bump, such as using asingle layer to form the bump, using other methods of patterning thefirst metallic adhesion layer 90 and the first metallic structural layer92, or the like.

FIG. 10 shows a second patterned photoresist layer 94 and a firstmetallization layer 96 added to the semiconductor die 78 illustrated inFIG. 9. The first metallization layer 96 includes a second metallicadhesion layer 98 and a second metallic structural layer 100. The secondpatterned photoresist layer 94 is formed over the second insulator layer86. The second metallic adhesion layer 98 is formed over the secondpatterned photoresist layer 94, the second insulator layer 86, and thefirst metallic structural layer 92. The second metallic structural layer100 is formed over the second metallic adhesion layer 98. The secondmetallic adhesion layer 98 may include Titanium, Chromium, TitaniumTungsten alloy, or other suitable material, and is used to bond thesecond metallic structural layer 100 to the substrate insulator layer82, to the first metallic structural layer 92, or both. The secondmetallic structural layer 100 may include Gold, Copper, or Aluminum. Inalternate embodiments of the present invention, the first metallizationlayer 96 may be a single layer, may include multiple layers, the secondmetallic adhesion layer 98 may include other conductive material, thesecond metallic structural layer 100 may include other conductivematerial, or any combination thereof.

FIG. 11 shows the remnants of the first metallization layer 96 afterlifting-off the portion of the first metallization layer 96 that wasformed over the second patterned photoresist layer 94 as illustrated inFIG. 10. Alternate embodiments of the present invention may use othertechniques to pattern the first metallization layer 96, such as using asingle layer to provide the first metallization layer 96, using othermethods of patterning the second metallic adhesion layer 98, using othermethods of patterning the second metallic structural layer 100, or thelike.

FIG. 12 shows a third insulator layer 102 and a third patternedphotoresist layer 104 added to the semiconductor die 78 illustrated inFIG. 11. The third insulator layer 102 is formed over the secondmetallic structural layer 100 and the second insulator layer 86. In oneembodiment of the present invention, the third insulator layer 102 isdeposited over the second metallic structural layer 100 using plasmaenhanced chemical vapor deposition (PECVD). In another embodiment of thepresent invention, the third insulator layer 102 is deposited over thesecond metallic structural layer 100 by sputtering. The third patternedphotoresist layer 104 is formed over the third insulator layer 102. Thethird insulator layer 102 may include Silicon Nitride, Silicon Dioxide,or Aluminum Oxide. Areas of the third insulator layer 102 not covered bythe third patterned photoresist layer 104 are etched away. In oneembodiment of the present invention, the third insulator layer 102 isetched using reactive ion etching (RIE). FIG. 13 shows the remnants ofthe third insulator layer 102 after etching away a portion of the thirdinsulator layer 102 illustrated in FIG. 12, and after removing the thirdpatterned photoresist layer 104 after etching. Alternate embodiments ofthe present invention may use other ways of patterning the thirdinsulator layer 102.

FIG. 14 shows a first sacrificial layer 106 and a fourth patternedphotoresist layer 108 added to the semiconductor die 78 illustrated inFIG. 13. The first sacrificial layer 106 is formed over the thirdinsulator layer 102 and the second metallic structural layer 100. Thefourth patterned photoresist layer 108 is formed over the firstsacrificial layer 106. The first sacrificial layer 106 will be used toprovide clearance between the movable contact 24 and the fixed contact26 of the first insulated-actuator MEMS switch 36. Areas of the firstsacrificial layer 106 not covered by the fourth patterned photoresistlayer 108 are etched away. In one embodiment of the present invention,the first sacrificial layer 106 is etched using RIE. In anotherembodiment of the present invention, the first sacrificial layer 106 isetched using wet etching.

FIG. 15 shows the remnants of the first sacrificial layer 106 afteretching away a portion of the first sacrificial layer 106 and afterremoving the fourth patterned photoresist layer 108 after etching, andshows a second metallization layer 110 added to the semiconductor die 78illustrated in FIG. 14. The second metallization layer 110 includes athird metallic adhesion layer 112 and a third metallic structural layer114. The third metallic adhesion layer 112 is formed over the thirdinsulator layer 102, the second metallic structural layer 100, and thefirst sacrificial layer 106. The third metallic structural layer 114 isformed over the third metallic adhesion layer 112. Alternate embodimentsof the present invention may use other ways of patterning the firstsacrificial layer 106.

FIG. 16 shows a patterned photoresist mold 116 and a MEMS cantileverstructure layer 118 added to the semiconductor die 78 illustrated inFIG. 15. The patterned photoresist mold 116 is formed over the thirdmetallic structural layer 114. The MEMS cantilever structure layer 118is then formed over the portion of the third metallic structural layer114 that is not covered by the patterned photoresist mold 116. The MEMScantilever structure layer 118 may formed over the third metallicstructural layer 114 by electroplating or by another technique. Thesecond metallization layer 110 may function as a seed layer for the MEMScantilever structure layer 118. After the MEMS cantilever structurelayer 118 is formed, the patterned photoresist mold 116 is removed.

FIG. 17 shows the remnants of the second metallization layer 110 and theMEMS cantilever structure layer 118 after etching away a portion of thesecond metallization layer 110 and the MEMS cantilever structure layer118 illustrated in FIG. 16. In one embodiment of the present invention,the third insulator layer 102 protects the first metallization layer 96from being undercut as a result of etching the second metallizationlayer 110. FIG. 18 shows a patterned second sacrificial layer 120 addedto the semiconductor die 78 illustrated in FIG. 17. The patterned secondsacrificial layer 120 is formed over the MEMS cantilever structure layer118, the third metallic structural layer 114, the third metallicadhesion layer 112, the first sacrificial layer 106, the third insulatorlayer 102, and the second metallic structural layer 100.

FIG. 19 shows a dome layer 122 added to the semiconductor die 78illustrated in FIG. 18 to provide the first insulated-actuator MEMSswitch 36. The dome layer 122 is formed over the patterned secondsacrificial layer 120 to provide a dome for the first insulated-actuatorMEMS switch 36. The first sacrificial layer 106 and the patterned secondsacrificial layer 120 were evacuated to provide space for the firstinsulated-actuator MEMS switch 36 to operate freely. The firstsacrificial layer 106 and the patterned second sacrificial layer 120 mayhave been evacuated through evacuation passages, holes, or both in thedome layer 122, in the third insulator layer 102, in the firstmetallization layer 96, or any combination thereof. The dome layer 122may include insulating material or conducting material. In oneembodiment of the present invention, the dome layer 122 is conductingand the third insulator layer 102 electrically insulates the dome layer122 from the first metallization layer 96.

The MEMS cantilever structure layer 118, the third metallic structurallayer 114, and the third metallic adhesion layer 112 provide thecantilever 22. The second metallic structural layer 100 provides thefixed contact 26, and the third metallic adhesion layer 112 provides themovable contact 24. The first metallization layer 96 provides theactuator 32 and the third insulator layer 102 provides the actuatorinsulator 38. The fixed contact 26 is electrically coupled to the firstterminal 28 (FIG. 3A) through the second metallic structural layer 100,the second terminal 30 (FIG. 3A) is electrically coupled to the movablecontact 24 through the third metallic adhesion layer 112, and theactuator 32 is electrically coupled to the control terminal 34 (FIG. 3A)through the first metallization layer 96.

In alternate embodiments of the first insulated-actuator MEMS switch 36,a non-cantilever architecture may be used, a different movable memberinstead of the cantilever 22 may be used, the fixed contact 26, themovable contact 24, the actuator 32, the actuator insulator 38, thecantilever 22, or any combination thereof may be provided using adifferent architecture. Additional layers may be included in any order.Any of the first insulator layer 84, the second insulator layer 86, thefirst metallic adhesion layer 90, the first metallic structural layer92, the second metallic adhesion layer 98, the second metallicstructural layer 100, the third metallic adhesion layer 112, the thirdmetallic structural layer 114, the MEMS cantilever structure layer 118,and the dome layer 122 may be omitted.

FIG. 20 shows a second region of the semiconductor die 78, according toone embodiment of the present invention. The semiconductor die 78includes the substrate 80, which may be a semiconductor substrate, suchas Silicon. The substrate insulator layer 82 is over the substrate 80and includes the first insulator layer 84 and the second insulator layer86. The first insulator layer 84 may include Silicon Nitride and thesecond insulator layer 86 may include Silicon Dioxide. In alternateembodiments of the present invention, the substrate insulator layer 82may be a single layer, may include multiple layers, the first insulatorlayer 84 may include other insulating material, the second insulatorlayer 86 may include other insulating material, or any combinationthereof.

FIG. 21 shows the second patterned photoresist layer 94 and the firstmetallization layer 96 added to the semiconductor die 78 illustrated inFIG. 20. The first metallization layer 96 includes the second metallicadhesion layer 98 and the second metallic structural layer 100. Thesecond patterned photoresist layer 94 is formed over the secondinsulator layer 86. The second metallic adhesion layer 98 is formed overthe second patterned photoresist layer 94 and the second insulator layer86. The second metallic structural layer 100 is formed over the secondmetallic adhesion layer 98. The second metallic adhesion layer 98 mayinclude Titanium or Chromium and is used to bond the second metallicstructural layer 100 to the substrate insulator layer 82. The secondmetallic structural layer 100 may include Gold, Copper, or Aluminum. Inalternate embodiments of the present invention, the first metallizationlayer 96 may be a single layer, may include multiple layers, the secondmetallic adhesion layer 98 may include other conductive material, thesecond metallic structural layer 100 may include other conductivematerial, or any combination thereof.

FIG. 22 shows the remnants of the first metallization layer 96 afterlifting-off the portion of the first metallization layer 96 that wasformed over the second patterned photoresist layer 94 as illustrated inFIG. 21. Alternate embodiments of the present invention may use othertechniques to pattern the first metallization layer 96, such as using asingle layer to provide the first metallization layer 96, using othermethods of patterning the second metallic adhesion layer 98, using othermethods of patterning the second metallic structural layer 100, or thelike.

FIG. 23 shows the third insulator layer 102 and the third patternedphotoresist layer 104 added to the semiconductor die 78 illustrated inFIG. 22. The third insulator layer 102 is formed over the secondmetallic structural layer 100 and the second insulator layer 86. In oneembodiment of the present invention, the third insulator layer 102 isdeposited over the second metallic structural layer 100 using PECVD. Inanother embodiment of the present invention, the third insulator layer102 is deposited over the second metallic structural layer 100 bysputtering. The third patterned photoresist layer 104 is formed over thethird insulator layer 102. The third insulator layer 102 may includeSilicon Nitride, Silicon Dioxide, or Aluminum Oxide. Areas of the thirdinsulator layer 102 not covered by the third patterned photoresist layer104 are etched away. In one embodiment of the present invention, thethird insulator layer 102 is etched using RIE. FIG. 24 shows theremnants of the third insulator layer 102 after etching away a portionof the third insulator layer 102 illustrated in FIG. 23, and afterremoving the third patterned photoresist layer 104 after etching.Alternate embodiments of the present invention may use other ways ofpatterning the third insulator layer 102.

FIG. 25 shows the first sacrificial layer 106 and the fourth patternedphotoresist layer 108 added to the semiconductor die 78 illustrated inFIG. 24. The first sacrificial layer 106 is formed over the thirdinsulator layer 102 and the second metallic structural layer 100. Thefourth patterned photoresist layer 108 is formed over the firstsacrificial layer 106. The first sacrificial layer 106 will be used toprovide clearance between the cantilever 42, which functions as themovable capacitive plate, and the capacitive dielectric 54 of thealternate MEMS switching capacitive element 56. Areas of the firstsacrificial layer 106 not covered by the fourth patterned photoresistlayer 108 are etched away. In one embodiment of the present invention,the first sacrificial layer 106 is etched using RIE. In anotherembodiment of the present invention, the first sacrificial layer 106 isetched using wet etching.

FIG. 26 shows the remnants of the first sacrificial layer 106 afteretching away a portion of the first sacrificial layer 106 and shows thesecond metallization layer 110 added to the semiconductor die 78illustrated in FIG. 25. The second metallization layer 110 includes thethird metallic adhesion layer 112 and the third metallic structurallayer 114. The third metallic adhesion layer 112 is formed over thethird insulator layer 102, the second metallic structural layer 100, andthe first sacrificial layer 106. The third metallic structural layer 114is formed over the third metallic adhesion layer 112. Alternateembodiments of the present invention may use other ways of patterningthe first sacrificial layer 106.

FIG. 27 shows the patterned photoresist mold 116 and the MEMS cantileverstructure layer 118 added to the semiconductor die 78 illustrated inFIG. 26. The patterned photoresist mold 116 is formed over the thirdmetallic structural layer 114. The MEMS cantilever structure layer 118is then formed over the portion of the third metallic structural layer114 that is not covered by the patterned photoresist mold 116. The MEMScantilever structure layer 118 may be formed over the third metallicstructural layer 114 by electroplating or by another technique. Thesecond metallization layer 110 may function as a seed layer for the MEMScantilever structure layer 118. After the MEMS cantilever structurelayer 118 is formed, the patterned photoresist mold 116 is removed.

FIG. 28 shows the remnants of the second metallization layer 110 and theMEMS cantilever structure layer 118 after etching away a portion of thesecond metallization layer 110 and the MEMS cantilever structure layer118 illustrated in FIG. 27. In one embodiment of the present invention,the third insulator layer 102 protects the first metallization layer 96from being undercut as a result of etching the second metallizationlayer 110. FIG. 29 shows the patterned second sacrificial layer 120added to the semiconductor die 78 illustrated in FIG. 28. The patternedsecond sacrificial layer 120 is formed over the MEMS cantileverstructure layer 118, the third metallic structural layer 114, the thirdmetallic adhesion layer 112, the first sacrificial layer 106, the thirdinsulator layer 102, and the second metallic structural layer 100.

FIG. 30 shows the dome layer 122 added to the semiconductor die 78illustrated in FIG. 29 to provide the alternate MEMS switchingcapacitive element 56. The dome layer 122 is formed over the patternedsecond sacrificial layer 120 to provide a dome for the alternate MEMSswitching capacitive element 56. The first sacrificial layer 106 and thepatterned second sacrificial layer 120 were evacuated to provide spacefor the alternate MEMS switching capacitive element 56 to operatefreely. The first sacrificial layer 106 and the patterned secondsacrificial layer 120 may have been evacuated through evacuationpassages, holes, or both in the dome layer 122, in the third insulatorlayer 102, in the first metallization layer 96, or any combinationthereof. The dome layer 122 may include insulating material orconducting material. In one embodiment of the present invention, thedome layer 122 is conducting and the third insulator layer 102electrically insulates the dome layer 122 from the first metallizationlayer 96.

The MEMS cantilever structure layer 118, the third metallic structurallayer 114, and the third metallic adhesion layer 112 provide thecantilever 42, which functions as the movable capacitive plate. Thefirst metallization layer 96 provides the combined actuator and fixedcapacitive plate 57 and the third insulator layer 102 provides thecapacitive dielectric 54. The first terminal 44 (FIG. 4B) iselectrically coupled to the combined actuator and fixed capacitive plate57 through the first metallization layer 96. The second terminal 48(FIG. 4B) is electrically coupled to the cantilever 42 through thesecond metallization layer 110.

In alternate embodiments of the alternate MEMS switching capacitiveelement 56, a non-cantilever architecture may be used, a differentmovable member instead of the cantilever 42 may be used, the movablecapacitive plate, the combined actuator and fixed capacitive plate 57,the capacitive dielectric 54, or any combination thereof may be providedusing a different architecture. Additional layers may be included in anyorder. Any of the first insulator layer 84, the second insulator layer86, the first metallic adhesion layer 90, the first metallic structurallayer 92, the second metallic adhesion layer 98, the second metallicstructural layer 100, the third metallic adhesion layer 112, the thirdmetallic structural layer 114, the MEMS cantilever structure layer 118,and the dome layer 122 may be omitted.

In another embodiment of the present invention, the semiconductor die 78may provide the first MEMS switching capacitive element 40 by separatingthe combined actuator and fixed capacitive plate 57 illustrated in FIG.30 into a separate actuator 50 and fixed capacitive plate 46.

FIG. 31 shows a third region of the semiconductor die 78, according toone embodiment of the present invention. The semiconductor die 78includes the substrate 80, which may be a semiconductor substrate, suchas Silicon. The substrate insulator layer 82 is over the substrate 80and includes the first insulator layer 84 and the second insulator layer86. The first insulator layer 84 may include Silicon Nitride and thesecond insulator layer 86 may include Silicon Dioxide. In alternateembodiments of the present invention, the substrate insulator layer 82may be a single layer, may include multiple layers, the first insulatorlayer 84 may include other insulating material, the second insulatorlayer 86 may include other insulating material, or any combinationthereof.

FIG. 32 shows the second patterned photoresist layer 94 and the firstmetallization layer 96 added to the semiconductor die 78 illustrated inFIG. 31. The first metallization layer 96 includes the second metallicadhesion layer 98 and the second metallic structural layer 100. Thesecond patterned photoresist layer 94 is formed over the secondinsulator layer 86. The second metallic adhesion layer 98 is formed overthe second patterned photoresist layer 94 and the second insulator layer86. The second metallic structural layer 100 is formed over the secondmetallic adhesion layer 98. The second metallic adhesion layer 98 mayinclude Titanium, Chromium, Titanium Tungsten alloy, or other suitablematerial, and is used to bond the second metallic structural layer 100to the substrate insulator layer 82. The second metallic structurallayer 100 may include Gold, Copper, or Aluminum. In alternateembodiments of the present invention, the first metallization layer 96may be a single layer, may include multiple layers, the second metallicadhesion layer 98 may include other conductive material, the secondmetallic structural layer 100 may include other conductive material, orany combination thereof.

FIG. 33 shows the remnants of the first metallization layer 96 afterlifting-off the portion of the first metallization layer 96 that wasformed over the second patterned photoresist layer 94 as illustrated inFIG. 32. Alternate embodiments of the present invention may use othertechniques to pattern the first metallization layer 96, such as using asingle layer to provide the first metallization layer 96, using othermethods of patterning the second metallic adhesion layer 98, using othermethods of patterning the second metallic structural layer 100, or thelike.

FIG. 34 shows the third insulator layer 102 and the third patternedphotoresist layer 104 added to the semiconductor die 78 illustrated inFIG. 33. The third insulator layer 102 is formed over the secondmetallic structural layer 100 and the second insulator layer 86. In oneembodiment of the present invention, the third insulator layer 102 isdeposited over the second metallic structural layer 100 using PECVD. Inanother embodiment of the present invention, the third insulator layer102 is deposited over the second metallic structural layer 100 bysputtering. The third patterned photoresist layer 104 is formed over thethird insulator layer 102. The third insulator layer 102 may includeSilicon Nitride, Silicon Dioxide, or Aluminum Oxide. Areas of the thirdinsulator layer 102 not covered by the third patterned photoresist layer104 are etched away. In one embodiment of the present invention, thethird insulator layer 102 is etched using RIE. FIG. 35 shows theremnants of the third insulator layer 102 after etching away a portionof the third insulator layer 102 illustrated in FIG. 34, and afterremoving the third patterned photoresist layer 104 after etching.Alternate embodiments of the present invention may use other ways ofpatterning the third insulator layer 102.

FIG. 36 shows the second metallization layer 110, the patternedphotoresist mold 116, and the MEMS cantilever structure layer 118 addedto the semiconductor die 78 illustrated in FIG. 35. The secondmetallization layer 110 includes the third metallic adhesion layer 112and the third metallic structural layer 114. The third metallic adhesionlayer 112 is formed over the third insulator layer 102, the secondmetallic structural layer 100, and the second insulator layer 86. Thethird metallic structural layer 114 is formed over the third metallicadhesion layer 112. The patterned photoresist mold 116 is formed overthe third metallic structural layer 114. The MEMS cantilever structurelayer 118 is then formed over the portion of the third metallicstructural layer 114 that is not covered by the patterned photoresistmold 116. The MEMS cantilever structure layer 118 may be formed over thethird metallic structural layer 114 by electroplating or by anothertechnique. The second metallization layer 110 may function as a seedlayer for the MEMS cantilever structure layer 118. After the MEMScantilever structure layer 118 is formed, the patterned photoresist mold116 is removed.

FIG. 37 shows the remnants of the second metallization layer 110 and theMEMS cantilever structure layer 118 after etching away a portion of thesecond metallization layer 110 and the MEMS cantilever structure layer118 illustrated in FIG. 36 to provide the first integrated fixedcapacitive element 58. The MEMS cantilever structure layer 118, thethird metallic structural layer 114, and the third metallic adhesionlayer 112 provide the first capacitive plate 59. The first metallizationlayer 96 provides the second capacitive plate 62, and the thirdinsulator layer 102 provides the fixed dielectric 66, which is betweenthe first and second capacitive plates 59, 62. The first capacitiveplate 59 is electrically coupled to the first terminal 60 (FIG. 4C)through the first metallization layer 96, and the second capacitiveplate 62 is electrically coupled to the second terminal 64 (FIG. 4C)through the second metallization layer 110.

In alternate embodiments of the first integrated fixed capacitiveelement 58, the first capacitive plate 59, the first terminal 60, thesecond capacitive plate 62, the second terminal 64, the fixed dielectric66, or any combination thereof may be provided using a differentarchitecture. Additional layers may be included in any order. Any of thefirst insulator layer 84, the second insulator layer 86, the secondmetallic adhesion layer 98, the second metallic structural layer 100,the third metallic adhesion layer 112, the third metallic structurallayer 114, and the MEMS cantilever structure layer 118, may be omitted.

An application example of an integrated selectable capacitor bank 68 isits use in a frequency synthesizer 124 in a mobile terminal 126, thebasic architecture of which is represented in FIG. 38. The mobileterminal 126 may include a receiver front end 128, a radio frequencytransmitter section 130, an antenna 132, a duplexer or switch 134, abaseband processor 136, a control system 138, the frequency synthesizer124, and an interface 140. The receiver front end 128 receivesinformation bearing radio frequency signals from one or more remotetransmitters provided by a base station (not shown). A low noiseamplifier (LNA) 142 amplifies the signal. A filter circuit 144 minimizesbroadband interference in the received signal, while down conversion anddigitization circuitry 146 down converts the filtered, received signalto an intermediate or baseband frequency signal, which is then digitizedinto one or more digital streams. The receiver front end 128 typicallyuses one or more mixing frequencies generated by the frequencysynthesizer 124. The baseband processor 136 processes the digitizedreceived signal to extract the information or data bits conveyed in thereceived signal. This processing typically comprises demodulation,decoding, and error correction operations. As such, the basebandprocessor 136 is generally implemented in one or more digital signalprocessors (DSPs).

On the transmit side, the baseband processor 136 receives digitizeddata, which may represent voice, data, or control information, from thecontrol system 138, which it encodes for transmission. The encoded datais output to the transmitter 130, where it is used by a modulator 148 tomodulate a carrier signal that is at a desired transmit frequency. Poweramplifier circuitry 150 amplifies the modulated carrier signal to alevel appropriate for transmission, and delivers the amplified andmodulated carrier signal to the antenna 132 through the duplexer orswitch 134.

A user may interact with the mobile terminal 126 via the interface 140,which may include interface circuitry 152 associated with a microphone154, a speaker 156, a keypad 158, and a display 160. The interfacecircuitry 152 typically includes analog-to-digital converters,digital-to-analog converters, amplifiers, and the like. Additionally, itmay include a voice encoder/decoder, in which case it may communicatedirectly with the baseband processor 136. The microphone 154 willtypically convert audio input, such as the user's voice, into anelectrical signal, which is then digitized and passed directly orindirectly to the baseband processor 136. Audio information encoded inthe received signal is recovered by the baseband processor 136, andconverted by the interface circuitry 152 into an analog signal suitablefor driving the speaker 156. The keypad 158 and display 160 enable theuser to interact with the mobile terminal 126, input numbers to bedialed, address book information, or the like, as well as monitor callprogress information.

Those skilled in the art will recognize improvements and modificationsto the preferred embodiments of the present invention. All suchimprovements and modifications are considered within the scope of theconcepts disclosed herein and the claims that follow.

1. A method to simultaneously form a micro-electromechanical systems(MEMS) switch and a MEMS fixed capacitor comprising: providing asubstrate; forming a first insulator layer over the substrate; forming acontact bump structure of a fixed contact of the MEMS switch from afirst structural metallization layer, wherein the first structuralmetallization layer is over the first insulator layer; forming anactuator of the MEMS switch, a first capacitive plate of the MEMS fixedcapacitor, and a contact portion of the fixed contact of the MEMS switchwith a first metallization layer, wherein the first metallization layeris over a portion of the first insulator layer and the contact bumpstructure; forming an actuator insulator of the MEMS switch and a fixeddielectric layer of the MEMS fixed capacitor with a second insulatorlayer, wherein the second insulator layer is over a portion of the firstmetallization layer and a portion of the first insulator layer; forminga first portion of a movable contact of the MEMS switch and a firstportion of a second capacitive plate of the MEMS fixed capacitor with asecond metallization layer, wherein the second metallization layer isover a portion of the first metallization layer, the actuator insulator,and the fixed contact of the MEMS switch, and wherein the secondmetallization layer is over a the fixed dielectric layer of the MEMSfixed capacitor; forming a second portion of the movable contact of theMEMS switch and a second portion of the second capacitive plate of theMEMS fixed capacitor with a cantilever structure layer, wherein thecantilever structure layer is over portion of the second metallizationlayer.
 2. The method of claim 1 further comprising: forming a dome ofthe MEMS switch with a dome layer, wherein the dome layer is over andabout the moveable contact of the MEMS switch, the fixed contact of theMEMS switch, and the actuator of the MEMS switch.
 3. The method of claim2 wherein the dome layer includes an insulating material.
 4. The methodof claim 2 wherein the dome layer includes a conducting material.
 5. Themethod of claim 1 wherein forming the first insulator layer over thesubstrate comprises: forming the first insulator layer with a pluralityof insulator layers.
 6. The method of claim 1 wherein forming thecontact bump structure of the fixed contact of the MEMS switch from thefirst structural metallization layer, wherein the first structuralmetallization layer is over the first insulator layer; comprises:forming a first patterned photoresist layer over the first insulatorlayer; forming a first metallic adhesion layer over the first patternedphotoresist layer and the first insulator layer; forming a firstmetallic structure layer over the first metallic adhesion layer; andlifting off a portion of the first metallic adhesion layer and the firstmetallic structure layer that were formed over the first patternedphotoresist layer to provide the contact bump structure of the fixedcontact of the MEMS switch.
 7. The method of claim 6 wherein the firstmetallic adhesion layer includes one of a group consisting of titanium,chromium, and a titanium tungsten alloy.
 8. The method of claim 6wherein the first metallic structure layer includes one of a groupconsisting of gold, copper, and aluminum.
 9. The method of claim 1wherein forming the actuator of the MEMS switch, the first capacitiveplate of the MEMS fixed capacitor, and the contact portion of the fixedcontact of the MEMS switch with the first metallization layer, whereinthe first metallization layer is over the portion of the first insulatorlayer and the contact bump structure comprises: forming a secondpatterned photoresist layer over the first insulator layer; forming asecond metallic adhesion layer over the first insulator layer, the firstpatterned photoresist layer, and the contact bump structure; forming asecond metallic structural layer over the second metallic adhesionlayer; and forming the contact portion of the fixed contact of the MEMSswitch, the actuator of the MEMS switch, and the first capacitive plateof the MEMS fixed capacitor by lifting off a portion of the secondmetallic adhesion layer and the second metallic structural layer thatwere formed over the second patterned photoresist layer.
 10. The methodof claim 9 wherein the second metallic adhesion layer includes one of agroup consisting of titanium, chromium, and a titanium tungsten alloy.11. The method of claim 9 wherein the second metallic structural layerincludes one of a group consisting of gold, copper, and aluminum. 12.The method of claim 1 wherein forming the actuator insulator of the MEMSswitch and the fixed dielectric layer of the MEMS fixed capacitor withthe second insulator layer, wherein the second insulator layer is overthe portion of the first metallization layer and the portion of thefirst insulator layer comprises: forming the second insulator layer bysputtering a second insulator material over the first metallizationlayer and the first insulator layer; and forming the actuator insulatorof the MEMS switch and the fixed dielectric layer of the MEMS fixedcapacitor by removing portions of the second insulator material of thesecond insulator layer.
 13. The method of claim 1 wherein the secondmetallization layer includes a third metallic structural layer; andwherein forming the first portion of the moveable contact of the MEMSswitch and the first portion of the second capacitive plate of the MEMSfixed capacitor with the second metallization layer comprises: formingthe second metallization layer over a portion a portion of the secondinsulator layer, the actuator insulator and the fixed contact of theMEMS switch and the first portion of the second capacitive plate of theMEMS fixed capacitor.
 14. The method of claim 1 wherein forming thesecond portion of the moveable contact of the MEMS switch and the secondportion of the second capacitive plate of the MEMS fixed capacitor withthe cantilever structure layer further comprises: forming a patternedphotoresist mold over a protected portion of the third metallicstructural layer; and forming the first portion of the moveable contactof the MEMS switch and the first portion of the second capacitive plateof the MEMS fixed capacitor over an exposed portion of the thirdmetallic structural layer with an electroplating technique.
 15. Themethod of claim 14 wherein forming the first portion of the moveablecontact of the MEMS switch and the first portion of the secondcapacitive plate of the MEMS fixed capacitor over the exposed portion ofthe third metallic structural layer with the electroplating techniquecomprises: removing the patterned photoresist mold over the protectedportion of the third metallic structural layer.
 16. Amicro-electromechanical systems (MEMS) switch and a MEMS fixed capacitorformed simultaneously comprising: a substrate; a first insulator layerformed over the substrate; a first structural metallization layer formedover the first insulator layer to provide a first portion of a fixedcontact of the MEMS switch; a first metallization layer formed over thefirst insulator layer to provide an actuator of the MEMS switch and afirst capacitive plate of the MEMS fixed capacitor, wherein the firstmetallization layer is further formed over the first portion of thefixed contact of the MEMS switch to provide a second portion of thefixed contact of the MEMS switch; a second insulator layer formed overthe first metallization layer and the first insulator layer to providean actuator insulator of the MEMS switch and a fixed dielectric layer ofthe MEMS fixed capacitor; a second metallization layer formed over thefirst metallization layer and above the actuator insulator and the fixedcontact of the MEMS switch to provide a first portion of a movablecontact of the MEMS switch, wherein a surface of the first portion ofthe movable contact, a surface of the actuator insulator, and a surfaceof the second portion of the fixed contact of the MEMS switchsubstantially define a clearance between the actuator insulator and thefixed contact of the MEMS switch and the movable contact of the MEMSswitch, and wherein the second metallization layer is further formedover the first insulator layer and the second insulator layer to providea first portion of a second capacitive plate of the MEMS fixedcapacitor; and a cantilever structure layer formed on the secondmetallization layer to provide a second portion of the movable contactof the MEMS switch and a second portion of the second capacitive plateof the MEMS fixed capacitor.
 17. The MEMS switch and the MEMS fixedcapacitor formed simultaneously of claim 16 wherein the first insulatorlayer formed over the substrate includes a plurality of insulatorlayers.
 18. The MEMS switch and the MEMS fixed capacitor formedsimultaneously of claim 16 wherein the first structural metallizationlayer includes a first metallic adhesion layer and a first metallicstructural layer.
 19. The MEMS switch and the MEMS fixed capacitorformed simultaneously of claim 18 wherein the first metallization layerincludes a second metallic adhesion layer and a second metallicstructural layer.
 20. The MEMS switch and the MEMS fixed capacitorformed simultaneously of claim 19 wherein the second metallization layerincludes a third metallic adhesion layer and a third metallic structurallayer.
 21. The MEMS switch and the MEMS fixed capacitor formedsimultaneously of claim 16 further comprising: a dome layer formed aboveand around the MEMS switch to provide a dome structure about the MEMSswitch, wherein interior walls of the dome structure are distinctlyseparated from the movable contact, the fixed contact, the actuator, andthe actuator insulator of the MEMS switch.
 22. The MEMS switch and theMEMS fixed capacitor of claim 21, wherein the dome structure includesevacuation passages.
 23. A plurality of micro-electromechanical systems(MEMS) devices comprising: a substrate having a first insulator layer ona surface of the substrate; a MEMS switch device including: a fixedcontact including a bump portion formed by a first metallization layeron the first insulator layer and a contact portion formed by a secondmetallization layer over a portion of the first metallization layer; aninsulated actuator including an actuator portion formed in part by thesecond metallization layer over the first insulator layer and aninsulator portion formed in part by a second insulator layer over theactuator portion; and a movable contact including a first cantileverportion formed by the second metallization layer and a second cantileverportion formed by a cantilever layer over the first cantilever portion,wherein the movable contact is configured to move towards the insulatedactuator upon actuation of the movable contact such that the movablecontact comes into contact with the fixed contact; and a MEMS fixedcapacitor including: a first fixed capacitive plate formed by a firstmetallization layer on the first insulator layer; a dielectric layer onthe first fixed capacitive plate formed by the second insulator layer;and a second fixed capacitive plate over the dielectric layer formed bythe second metallization layer.